Chemical mechanical polishing or planarization (CMP) processes are carried out to produce flat (planar) surfaces on a variety of materials including semiconductor wafers, glasses, hard disc substrates, sapphire wafers and windows, plastics and so forth. Typically, CMP processes involve use of a polymeric pad and a slurry that contains loose abrasive particles and other chemical additives to make possible the removal process by both chemical and mechanical actions.
During the process, the polishing pad becomes glazed with polishing residues and a conditioner is typically used to condition or dress polishing pads. Generally, tools for conditioning CMP pads, also known as CMP conditioners, or CMP dressers, are fabricated by using a metal bond (electroplated, brazed or sintered) to fix abrasive particles to a preform and create a tool surface that can condition polishing pads. In some cases, the conditioner not only conditions the glazed surface of the pad but can also generate pad texture or topography which can influence wafer surface quality. Inappropriate conditioning of the polishing pad can produce micro-scratches on the polished wafer surface and increase dishing.
CMP conditioners that are based on stainless steel substrates and manufactured through brazing or powder metal sintering technologies, tend to be susceptible to chemical attacks in highly corrosive environments, such as highly acidic tungsten (W) or copper (Cu) slurries, leading to premature failure of the conditioner. For instance, braze components such as nickel (Ni), chromium (Cr), and others are leached out of the bonding system, forming a porous metal bond microstructure, often at both surface and subsurface levels. In turn this accelerates the corrosion process due to increased surface area. Higher trace metal contents in the applied CMP slurry, also can lead to potential wafer contaminations.